... The Oxford economist Robert Allen recently estimated needs-based absolute poverty lines for rich countries that are designed to match more accurately the $1.90 line for poor countries, and $4 a day is around the middle of his estimates. When we compare absolute poverty in the United States with absolute poverty in India, or other poor countries, we should be using $4 in the United States and $1.90 in India.

Once we do this, there are 5.3 million Americans who are absolutely poor by global standards. This is a small number compared with the one for India, for example, but it is more than in Sierra Leone (3.2 million) or Nepal (2.5 million), about the same as in Senegal (5.3 million) and only one-third less than in Angola (7.4 million). Pakistan (12.7 million) has twice as many poor people as the United States, and Ethiopia about four times as many. ...